Role of growth hormone-releasing hormone in sleep and growth impairments induced by upper airway obstruction in rats

Upper airway obstruction (UAO) can lead to abnormal growth hormone (GH) homeostasis and growth retardation but the mechanisms are unclear. We explored the effect of UAO on hypothalamic GH-releasing hormone (GHRH), which has a role in both sleep and GH regulation. The tracheae of 22-day-old rats were narrowed; UAO and sham-operated animals were sacrificed 16 days post-surgery. To stimulate slow-wave sleep (SWS) and GH secretion, rats were treated with ritanserin (5-HT(2) receptor antagonist). Sleep was measured with a telemetric system. Hypothalamic GHRH, hypothalamic GHRH receptor (GHRHR) and GH receptor, and orexin were analysed using ELISA, real-time PCR and Western blot. UAO decreased hypothalamic GHRH, GHRHR and GH receptor levels, while orexin mRNA increased (p<0.01). In UAO rats, the duration of wakefulness was elevated and the duration of SWS, paradoxical sleep and slow-wave activity was reduced (p<0.001). Ritanserin alleviated these effects, i.e. normalised hypothalamic GHRH content, decreased wake duration, increased duration and depth of SWS, and attenuated growth impairment (p<0.001). Here, we present evidence that growth retardation in UAO is associated with a reduction in hypothalamic GHRH content. Our findings show that abnormalities in the GHRH/GH axis underlie both growth retardation and SWS-disorder UAO.

Antral computerized tomography pre-operative evaluation: relationship between mucosal thickening and maxillary sinus function

OBJECTIVES

to assess the correlation between maxillary sinus inferior mucosal thickening and sinus outflow obstruction.

MATERIAL AND METHODS

the study included 280 computerized tomography (CT) scans (560 maxillary sinuses). CT aimed to assess sinusitis; trauma to the face and intubated patients were excluded. Mucosal thickening was graded as < 5 mm (1), < 10 mm (2), < 15 mm (3), < 20 mm (4) and > 20 mm (5), and classified by appearance as normal, rounded, circumferential, irregular, or complete. Maxillary sinus outflow was classified as patent or obstructed.

RESULTS

mucosal thickening was found in 36.1% of the maxillary sinuses, graded as 31.2% (1), 34.2% (2), 12.9% (3), 5.4% (4) and 16.3% (5), and classified as rounded (11.8%), irregular (10.4%), circumferential (8.8%) and complete (5.2%). Sinus outflow was obstructed in 15% of the scans. Mucosal thickening of < 5 mm (11.1%), < 10 mm (36.2%) and > 10 mm (74.3%) was associated with sinus obstruction (P<0.0001). Rounded (6.1%), circumferential (55.2%), irregular (38.8%) and complete (100%) mucosal appearances were associated with sinus obstruction (P<0.001). When statistically combined, a substantial risk for sinus obstruction was observed with irregular mucosal appearance of > 5 mm (56.5% for grade 2 up to 82.6% for grades 3-5) and circumferential appearance (21.4% for grade 1 up to 100% for grades 3-5). A low risk for obstruction was found with the rounded appearance (mean 6.1%).

CONCLUSIONS

irregular (> 5 mm), circumferential and complete mucosal appearance are associated with an increased risk for sinus outflow obstruction and an ENT consultation is recommended. A rounded mucosal appearance of any grade is associated with a low risk for sinus obstruction. Routine CT scans, including the maxillary sinus ostium, are recommended.

AGGRESSIVE INTRACRANIAL DURAL ARTERIOVENOUS FISTULA PRESENTING WITH CEREBROSPINAL FLUID RHINORRHEA

OBJECTIVE

This is the first report of an aggressive dural arteriovenous fistula presenting with rhinorrhea. It demonstrates the importance of recognizing increased intracranial pressure, and its underlying cause, as the predisposing factor to a spontaneous cerebrospinal fluid leak because this carries implications for management.

CLINICAL PRESENTATION

Ten years after minor trauma and directly after an intercontinental flight, a 43-year-old woman presented with rhinorrhea. Right-sided pulsatile tinnitus had been present for the past 9 years. Imaging demonstrated an intracranial dural arteriovenous fistula of the right transverse sinus with cortical venous reflux. Magnetic resonance imaging findings indicated long-standing increased intracranial pressure.

INTERVENTION

The fistula was treated by endovascular means, using both transvenous and transarterial approaches, which led to immediate relief of the tinnitus and resolution of the rhinorrhea within 4 days.

CONCLUSION

A dural arteriovenous fistula should be included in the differential diagnosis of underlying causes of increased intracranial pressure when examining a patient with a cerebrospinal fluid leak. Treatment of the fistula should precede attempts to treat the rhinorrhea, especially if the fistula has cortical venous reflux.

Selective impairment of prediction error signaling in human dorsolateral but not ventral striatum in Parkinson's disease patients: evidence from a model-based fMRI study

Animal studies have found that the phasic activity of dopamine neurons during reward-related learning resembles a "prediction error" (PE) signal derived from a class of computational models called reinforcement learning (RL). An apparently similar signal can be measured using fMRI in the human striatum, a primary dopaminergic target. However, the fMRI signal does not measure dopamine per se, and therefore further evidence is needed to determine if these signals are related to each other. Parkinson's disease (PD) involves the neurodegeneration of the dopamine system and is accompanied by deficits in reward-related decision-making tasks. In the current study we used a computational RL model to assess striatal error signals in PD patients performing an RL task during fMRI scanning. Results show that error signals were preserved in ventral striatum of PD patients, but impaired in dorsolateral striatum, relative to healthy controls, a pattern reflecting the known selective anatomical degeneration of dopamine nuclei in PD. These findings support the notion that PE signals measured in the human striatum by the BOLD signal may reflect phasic DA activity. These results also provide evidence for a deficiency in PE signaling in the dorsolateral striatum of PD patients that may offer an explanation for their deficits observed in other reward learning tasks.

Attachment-oriented endoscopic surgical strategy for sinonasal inverted papilloma

BACKGROUND

It is well documented that inverted papillomas (IP) have a localized attachment site. Still, instead of concentrating on the attachment site, endoscopic surgeons often perform an extended resection similar to the one achieved after external surgery.

OBJECTIVE

Our objective was to evaluate an attachment-oriented endoscopic surgical strategy and to determine IP attachment diameter and location.

METHODS

A prospective study was conducted. Thirty-three consecutive patients who underwent endoscopic IP excision (2001--2007) were enrolled. Thirty patients had adequate follow-up. Attachment diameters were measured in 25/33 patients. Surgery included debulking, identifying the precise mucosal attachment site, subperiosteal dissection and excision of the attachment, frozen section control, and resection/drilling of underlying bone.

RESULTS

The mean measured attachment diameter (n = 25) was 8.4 +/- 6 mm (range, 3-23 mm). Attachment locations included maxillary sinus (39%), ethmoid sinus (21%), nasal cavity (21%), frontal sinus (6%), sphenoid sinus (6%), lamina papyracea (3%), and cribriform plate (3%). The mean follow-up (n = 30) was 40 +/- 21 months. Three patients had Krouse stage 1, 10 patients had stage 2, and 17 patients had stage 3. Nine patients had undergone previous surgeries. After attachment-oriented endoscopic surgery, three patients had persistent disease. Nasolacrimal duct stenosis was the only complication (n = 1).

CONCLUSION

Even advanced IP have small attachments. Their Identification facilitates efficacious resection with minimal morbidity.

Age-dependent spatial memory loss can be partially restored by immune activation

Aging is often associated with a decline in hippocampus-dependent spatial memory. Here, we show that functional cell-mediated immunity is required for the maintenance of hippocampus-dependent spatial memory. Sudden imposition of immune compromise in young mice caused spatial memory impairment, whereas immune reconstitution reversed memory deficit in immune-deficient mice. Analysis of hippocampal gene expression suggested that immune-dependent spatial memory performance was associated with the expression of insulin-like growth factor (Igf1) and of genes encoding proteins related to presynaptic activity (Syt10, Cplx2). We further showed that memory loss in aged mice could be attributed to age-related attenuation of the immune response and could be reversed by immune system activation. Homeostatic-driven proliferation of lymphocytes, which expands the existing T cell repertoire, restored spatial memory deficits in aged mice. Thus, our results identify a novel function of the immune system in the maintenance of spatial memory and suggest an original approach for arresting or reversing age-associated memory loss.

Systemic and renal growth hormone-IGF1 axis involvement in a mouse model of type 2 diabetes

AIMS/HYPOTHESIS

In previous studies we have shown a significant involvement of the growth hormone (GH)-IGF axis in animal models of type 1 diabetes mellitus, but the role of this endocrine system in type 2 diabetes mellitus is less well characterised. We therefore examined the endocrine and renal GH-IGF axis changes in db/db mice, a model of type 2 diabetes mellitus and nephropathy.

MATERIALS AND METHODS

Obese and lean animals were followed, beginning at hyperglycaemia onset, for 4 weeks. Albuminuria and creatinine clearance, as well as kidney and glomerular morphology were assessed. Tissue protein levels were determined by western blotting and mRNA levels by RT-PCR.

RESULTS

Serum GH and IGF1 levels immediately prior to killing were decreased and liver mRNA levels of insulin-like growth factor binding protein 1 (Igfbp1) were increased in obese animals. Kidney weight was increased in obese animals, associated with hyperfiltration, albuminuria and glomerular hypertrophy. Administration of a somatostatin analogue (PTR-313) did not improve any of these parameters of diabetic renal involvement. Renal Igf1 mRNA was decreased and renal Igfbp1 mRNA and protein were significantly increased in obese animals. Renal insulin-driven levels of phosphorylated forkhead box O1 (FOXO1) were decreased in obese animals.

CONCLUSIONS/INTERPRETATION

Diabetic db/db mice show significant renal changes (and IGFBP1 renal accumulation), similar to the findings in models of type 1 diabetes mellitus. A decreased signalling through the insulin receptor and decreased FOXO1 phosphorylation may allow Igfbp1 gene transcription. These renal changes are associated with low circulating IGF1 and GH levels and unchanged hepatic growth hormone receptor expression, unlike the condition in type 1 diabetes mellitus. This suggests that further GH inhibition to modulate renal complications in type 2 diabetes mellitus is not indicated.

Necrotizing Fasciitis of the Skull Base and Neck in a Patient with AIDS and Non-Hodgkin's Lymphoma

Necrotizing fasciitis is a rapidly progressing, life-threatening soft tissue bacterial infection found more frequently in immunocompromised subjects and rarely in the head and neck. We report a rare case of a patient with acquired immunodeficiency syndrome (AIDS) and non-Hodgkin's lymphoma (NHL) who presented with a high fever and supraorbital cellulitis 1 week after undergoing chemotherapy. He received intravenous antibiotic therapy but soon developed dyspnea and trismus with rapid extension of the cellulitis to the face, ipsilateral infratemporal fossa (ITF), and bilateral neck. An awake tracheotomy was followed by surgical exploration and drainage and debridement of the supraorbital and ITF areas, parotid gland, and bilateral neck. He received intravenous antibiotic therapy and the surgical wound was regularly debrided for 10 days. Following a gradual recovery, the patient was discharged 2 weeks later. Early antibiotic therapy, wide surgical exploration, and a secured airway are the therapeutic mainstay for necrotizing fasciitis of the skull base and neck.

Sonographic features of senile scleral calcification

BACKGROUND AND OBJECTIVE

To describe the sonographic features of senile scleral calcification using ultrasound biomicroscopy.

PATIENTS AND METHODS

Four patients in whom senile scleral calcifications were found incidentally on computed tomography studies underwent ultrasound biomicroscopy examination.

RESULTS

The senile scleral calcification was bilateral in three patients and unilateral in one patient. In all patients, the calcified material created the anterior shadowing typical of calcified lesions. The ultrasound biomicroscopy study localized the senile scleral calcification to the subconjunctival layer, superficially above the sclera, and anterior to the horizontal muscles.

CONCLUSIONS

This is the first description of the ultrasound biomicroscopy features of senile scleral calcification. Ultrasound biomicroscopy may serve as a good tool for the accurate localization of the plaque.

Systemic corticosteroids for allergic fungal rhinosinusitis and chronic rhinosinusitis with nasal polyposis: a comparative study

OBJECTIVES

To compare the effect of preoperative high-dose systemic corticosteroids on the radiographic and endoscopic appearance of allergic fungal rhinosinusitis (AFRS) and chronic rhinosinusitis with nasal polyposis (CRSwNP).

STUDY DESIGN AND SETTING

Eight AFRS and 10 CRSwNP patients underwent computed tomographic (CT) scans and then received preoperative 1 mg/kg prednisone for 10 days. CT scans were repeated 1 day before surgery and compared with pretreatment scans (Lund-MacKay radiologic scoring system). The endoscopic appearance was recorded intraoperatively.

RESULTS

The score dropped from 16 (66.4%) to 4.75 in the AFRS group and from 18.4 (23%) to 14.1 in the CRSwNP group (P=0.0064). Intraoperatively, most sinus mucosal surfaces appeared normal in the AFRS patients but were markedly edematous in the CRSwNP patients.

CONCLUSION

Radiographic response of AFRS to systemic corticosteroids is significantly greater compared with CRSwNP. This finding is supported by endoscopic observation.

Palpitations: could they be neurogenic? A case report

BACKGROUND

Palpitations usually occur in patients with arrhythmias of cardiac origion, in conditions associated with increased catecholamine levels, and in psychiatric disorders. A rare etiology of palpitations is seizures with autonomic features.

REVIEW SUMMARY

We report a 24-year-old man with a several-week history of episodic palpitations, weakness, dizziness, and presyncopal phenomena. Subsequent events included loss of consciousness, with postevent confusion and tonic movements. A low-grade astrocytoma was diagnosed in the right frontal lobe.

CONCLUSION

This case emphasizes the importance of detailed history in the diagnosis of epilepsy.

Stafne bone cavity--magnetic resonance imaging

A case of Stafne bone cavity (SBC) affecting the body of the mandible of a 51-year-old female is reported. The imaging modalities included panoramic radiograph, computed tomography (CT) and magnetic resonance (MR) imaging. Panoramic radiograph and CT were able to determine the outline of the cavity and its three dimensional shape, but failed to precisely diagnose the soft tissue content of the cavity. MR imaging demonstrated that the bony cavity is filled with soft tissue that is continuous and identical in signal with that of the submandibular salivary gland. Based on the MR imaging a diagnosis of SBC was made and no further studies or surgical treatment were initiated. MR imaging should be considered the diagnostic technique in cases where SBC is suspected. Recognition of the lesion should preclude any further treatment or surgical exploration.

A targeted endoscopic approach to chronic isolated frontal sinusitis

OBJECTIVE

Chronic isolated frontal sinusitis occurs infrequently. In this condition, most of the ethmoid cells are well aerated and the frontal sinus is involved secondary to anatomical obstruction or inflammatory changes confined to the frontal recess. The purpose of this study was to evaluate a targeted endoscopic technique where standard anterior ethmoidectomy is unnecessary in the treatment of chronic isolated frontal sinusitis.

STUDY DESIGN AND SETTING

This retrospective study was conducted in a large university-affiliated hospital and included 11 patients with chronic isolated frontal sinusitis who underwent endoscopic sinus surgery limited to the frontal sinus outflow. The ethmoid bulla was untouched in all cases. Follow-up continued for 19 to 40 months (mean 28.6 months).

RESULTS

Frontal sinus outflow patency was verified in 9 patients (81.8%). Nine patients, including one with an apparent nonpatent frontal ostium, reported improvement. Two patients-one of whom had a patent frontal ostium-reported no improvement. There were no complications.

CONCLUSION

Chronic isolated frontal sinusitis can be effectively treated in selected cases by a targeted endoscopic procedure, limited to reestablishment of frontal sinus outflow.

EBM RATING

C-4.

[Does percutaneous nephrolithotripsy (PCNL) affect renal function: assessment with quantitative spect of Tc 99M-DMSA (QDMSA) renal scintigraphy]

PURPOSE

The study aimed to quantitatively investigate the effect of PCNL on global and regional function using quantitative single photon emission computerized tomography (SPECT) measurement of Tc-dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA).

METHODS

Seventy nine patients with nephrolithiasis undergoing PCNL were studied by sequential QDMSA examination. There were 42 (53%) males and 37 (47%) females with mean age of 47 +/- 16 years. The initial study was conducted before PCNL procedure and the follow-up studies were performed 1.5-24 months after PCNL. Among 60 of the 79 (76%) patients, in whom PCNL was performed using upper or lower pole access, regional renal function of affected and non-affected pole of operated kidney was calculated separately.

RESULTS

There was no statistically significant difference between the uptake of treated kidney before and after PCNL procedure (11.9% +/- 5% vs 11.6% +/- 5%; t = 0.9, p = 0.368). The total renal functional volume of treated kidney was to be slightly decreased from 235cc +/- 62cc to 224cc +/- 59cc (t = 2.7; p = 0.011). The percent of injected dose per ml.. of renal tissue of treated kidney was not affected statistically (0.051 +/- 0.02 vs 0.053 +/- 0.02; t = 0.86, p = 0.296). In the assessment of the regional renal function of treated kidney, a statistically significant decrease in the functional renal volume was revealed at the part which underwent PCNL procedure (91cc +/- 30cc vs 82cc +/- 27cc; t = 2.64, p = 0.013). Regarding percent of injected dose per ml. of renal tissue, no statistically significant difference was found between the part of treated kidney, which underwent PCNL and non-affected area of the same kidney (0.049 +/- 0.02 vs 0.05 +/- 0.02; t = 0.693, p = 0.494). The function of contralateral kidney remained unchanged (13.4% +/- 5.2% vs 13.6% +/- 4.8%; t = 0.68, p = 0.5). Function volume, neither total percent uptake, nor percent of injected dose per ml. of renal tissue were reduced significantly. Further studies with long term follow-up of treated kidney are required.

Evoked potential studies in the antiphospholipid syndrome: differential diagnosis from multiple sclerosis

BACKGROUND

The CNS manifestations of the antiphospholipid syndrome (APS) can mimic multiple sclerosis both clinically and radiologically.

OBJECTIVE

To compare evoked potential studies in APS patients and patients with multiple sclerosis with similar neurological disability.

METHODS

30 APS patients with CNS manifestations and 33 patients with definite multiple sclerosis and similar neurological disability underwent studies of visual evoked potentials (VEP), somatosensory evoked potentials (SSEP) in the upper and lower limbs (UL, LL), and sympathetic skin responses (SSR) in the upper and lower limbs.

RESULTS

The neurological manifestations in the APS patients included stroke (n = 17), transient ischaemic attacks (n = 10), and severe headache with multiple white matter lesions on brain MRI (n = 3). Abnormal SSEP (LL), and SSR (UL; LL) were seen in APS patients (37%, 27%, and 30%, respectively) but VEP and UL SSEP were rarely abnormal (10% and 6%, respectively in APS v 58% and 33% in multiple sclerosis; p = 0.0005, p = 0.008). Mean VEP latencies were more prolonged in multiple sclerosis (116 ms v 101 ms, p<0.001). Only one APS patient had abnormal findings in all three evoked potential studies, compared with seven patients in the multiple sclerosis group (p = 0.04)

CONCLUSIONS

Abnormal VEPs are uncommon in APS in contrast to multiple sclerosis. Coexisting abnormalities in all other evoked potentials were similarly rare in APS. In patients with brain MRI findings compatible either with multiple sclerosis or APS, normal evoked potential tests, and especially a normal VEP, may support the diagnosis of APS.

White matter changes in multiple sclerosis: correlation of q-space diffusion MRI and 1H MRS

OBJECTIVE

To explore the diagnostic usefulness of high b-value diffusion magnetic resonance brain imaging ("q-space" imaging) in multiple sclerosis (MS). More specifically, we aimed at evaluating the ability of this methodology to identify tissue damage in the so-called normal-appearing white matter (NAWM).

DESIGN

In this study we examined the correlation between q-space diffusion imaging and magnetic resonance spectroscopy (MRS)-based two-dimensional 1H chemical shift imaging. Eight MS patients with different degree of disease severity and seven healthy subjects were scanned in a 1.5-T magnetic resonance imaging (MRI) scanner. The MRI protocol included diffusion tensor imaging (DTI) (with bmax of 1000 s/mm2), high b-value diffusion-weighted imaging (with bmax of 14,000 s/mm2) and 2D chemical shift imaging. The high b-value data set was analyzed using the q-space methodology to produce apparent displacement and probability maps.

RESULTS

We found that the q-space diffusion displacement and probability image intensities correlated well with N-acetylaspartate levels (r=.61 and .54, respectively). Furthermore, NAWM that was abnormal on MRS was also found to be abnormal using q-space diffusion imaging. In these areas, the q-space displacement values increased from 3.8+/-0.2 to 4.6+/-0.6 microm (P<.02), the q-space probability values decreased from 7.4+/-0.3 to 6.8+/-0.3 (P<.002), while DTI revealed only a small, but still significant, reduction in fractional anisotropy values from 0.40+/-0.02 to 0.37+/-0.02 (P<.05).

CONCLUSION

High b-value diffusion imaging can detect tissue damage in the NAWM of MS patients. Despite the theoretical limitation of this method, in practice it provides additional information which is clinically relevant for detection of tissue damage not seen in conventional imaging techniques.

Postoperative treatment of clinically nonfunctioning pituitary adenomas with dopamine agonists decreases tumour remnant growth

OBJECTIVE

There is no consensus as to the optimal postoperative treatment of patients with clinically nonfunctioning pituitary adenomas (NFPA) in whom total tumour removal has not been achieved. In this study we assessed whether dopamine agonist (DA) treatment can prevent postoperative remnant enlargement in NFPA.

DESIGN AND METHODS

Thirty-three patients (25 men/8 women; mean age, 61.7 +/- 11.2 years; mean follow-up, 40.6 +/- 4.8 months) were treated with DA, and their outcome was compared to that of 47 untreated patients (33 men/14 women; mean age, 59 +/- 2 years; mean follow-up, 42.9 +/- 4.2 months).

RESULTS

Tumour mass decreased or remained stable in 18/20 patients in whom DA treatment was initiated upon detection of residual tumour on postoperative MRI (group I). In 13 subjects (group II), DA therapy was started when tumour remnant growth became evident during the course of routine follow-up. Tumour growth stabilized or decreased in 8/13 (61.5%) of these patients. In contrast, tumour size remained stable in only 38.3% (18/47) of the untreated subjects (P < 0.0001 for comparisons among the three groups) and increased in the remaining 29 patients. Tumour enlargement free mean survival time was 103.7 +/- 8.8 months (CI 86.3-121) for group I, 43.9 +/- 9.6 months (CI 25.2-62.8) for group II and 36.7 +/- 3.8 (CI 29.2-44.2) for the control group (P = 0.0017). Treatment vs. control hazard ratio for tumour enlargement was 0.135 for group I (P = 0.007, 95% CI 0.032-0.577) and 0.892 for group II (P = 0.817; 95% CI 0.34-2.34).

CONCLUSIONS

Dopamine agonist therapy is associated with a decreased prevalence of residual tumour enlargement in patients with nonfunctioning pituitary adenomas, particularly when treatment is instituted before tumour remnant growth is detected.

Early CT changes and outcome of ischemic stroke

Although recombinant tissue plasminogen activator (rt-PA) was rapidly implemented as part of the emergency care of acute stroke, its use in daily clinical practice still remains controversial in many countries. The most important question is criteria for careful selection of subgroup of patients for this treatment. It has been hypothesized that early computed tomography (CT) changes of ischemia are risk factors for symptomatic intracerebral hemorrhage and poor outcome. We conducted a prospective outcome study of patients with acute ischemic stroke (IS) admitted to the hospital within 6 h of symptom onset. Experienced neuroradiologists blind to the clinical outcome of the patients read all CT scans carried out in the emergency room. Early CT changes were defined as in European Cooperative Acute Stroke Study (ECASS) 2. There were 150 patients (75 males, mean age 72.5 +/- 9.0) with acute IS (54.7% with mild stroke and 45.3% with severe stroke). Early CT changes were presented with tissue hypodensity - 55.7%, effacement of sulci - 41.3%, hyperdensity of middle cerebral artery (MCA) - 13.3%, hypodensity of lentiform - 20.7%, loss of insular ribbon sign - 28.7%. Follow-up after 30 days showed that 44% of the patients were discharged home, 20% were discharged to rehabilitation facilities, 22% were discharged to chronic care institutions and 14% died. Data were statistically analyzed. Our data suggest that early signs on CT scan could not predict outcome of patients with acute IS.

Leptin reverses the inhibitory effect of caloric restriction on longitudinal growth

Caloric imbalance, particularly in critical periods of growth and development, is often the underlying cause of growth abnormalities. Serum levels of leptin are elevated in obesity and are low in malnutrition and malabsorption. The aim of the present study was to determine whether leptin integrates energy levels and growth in vivo, as shown previously in our ex vivo experiments, even in the presence of caloric restriction. In the first part of the study, mice were divided into three groups. Two groups were fed ad libitum and received leptin or vehicle only, and the third group was pair-fed with the group injected with leptin to dissociate leptin's effect on growth from its effect on food consumption. Mice given leptin had a significantly greater tibial length than untreated pair-fed animals and a similar tibial length as control mice fed ad libitum despite their lower weight. In addition, leptin significantly increased the overall size of the epiphyseal growth plate by 11%. On immunohistochemistry and in situ hybridization studies, leptin stimulated both the proliferation and differentiation of tibial growth plate chondrocytes without affecting the overall organization of the plate. There was also a marked increase in the expression and level of IGF-IR. In the second part of the study, two groups of mice were fed only 60% of their normal chow; one was injected with leptin, and the other was injected with vehicle alone. Caloric deprivation by itself reduced serum levels of IGF-I by 70% and the length of the tibia by 5%. Leptin treatment corrected the fasting-induced growth deficiency, but further reduced the level of serum IGF-I. These results indicate that leptin stimulates growth even in the presence of caloric restriction independently of peripheral IGF-I.

Cortical lesions associated with transient neurological symptoms - not always a matter of cause and effect

The occurrence of transient recurrent stereotypical neurological events mandates the exclusion of an underlying brain lesion. When imaging studies demonstrate the presence of a structural brain lesion, a cause and effect relationship between the two entities is assumed, and the decision for surgical intervention may then follow almost automatically. We describe five patients with transient neurological events suspected as being seizures that were referred for surgery because of an associated structural brain lesion. Video electroencephalographic recordings revealed that the events that brought these patients to neurosurgical attention were non-epileptic seizures. None of these patients underwent surgical intervention, and all were referred for behavioral therapy. Therefore, even in the presence of a confirmed brain lesion, the presenting paroxysmal events may be of a non-organic origin and should not necessarily be assumed to be caused by the concomitantly existing structural abnormality.